Protesters march with banners and placards against private companies involved in NHS and social care services provision in central London on March 4, 2017. (AFP photo)

Britain’s departure from the European Union is projected to deliver a severe blow to the National Health Service (NHS), the country’s healthcare system, which already suffers from serious staff shortage.

Critics have warned that UK Prime Minister Theresa May is making the NHS staffing crisis worse by refusing to guarantee the rights of European citizens.

Britain’s withdrawal from the EU will force European healthcare workers to either stay away or leave the country. The country’s main association of nurses says it’s currently facing 24,000 nursing vacancies.

Almost 2,700 EU nurses quit their jobs in 2016, compared to 1,600 in 2014, an increase of 68 percent. In total, about 6,400 EU nationals quit the NHS in 2016, up from 5,135 in 2014.

There are an estimated 57,000 EU nationals working for the NHS, including 10,000 doctors and 20,000 nurses.

“The Government risks turning off the supply of qualified nurses from around the world at the very moment the health service is in a staffing crisis like never before,” said Janet Davies, Chief Executive and General Secretary of the Royal College of Nursing.

“As she pulls the trigger to begin negotiations, Theresa May must tell EU nurses and other occupations that they are needed and welcome in the NHS. It would not survive without their contribution,” she said.

“Sadly, it is no surprise that EU staff are leaving – they have been offered no security or reassurance that they will be able to keep their jobs. Few are able to live with such uncertainty.”

The NHS is already under pressure because of a long-term failure to hire enough people. The British Red Cross warned in January that the NHS is facing a “humanitarian crisis” as hospitals and ambulance services struggle to keep up with rising demand.

The warning came following the deaths of two patients after long waits on trolleys in hospital corridors in Worcester.